Stannous fluoride, SnF.sub.2, has been used in dentistry since the 1950's as a chemical adjunct to prevent dental caries. Topical applications of SnF.sub.2 consistently have shown dramatic reductions in dental caries activity with minimal side effect. Evidence has also accumulated that SnF.sub.2 has antibacterial properties which may affect its anticaries properties as well as inhibit plaque formation and gingivitis. See Tinanoff, "Review of the Antimicrobial Action of Stannous Fluoride," 1990.
Addy et al., 1988, reported a densensitizing effect for fresh SnF.sub.2 due to a covering or obturation of tubules in hypersensitive dentine. There is also an indication that SnF.sub.2 may be effective in controlling Candida sp. colorization of denture plaque.
Prescription (R.sub.x) nonaqueous gels of glycerine and SnF.sub.2, such as Scherer Laboratory's, Gel-Kem are perhaps the most widely used form of R.sub.x SnF.sub.2 available commercially. These gels are generally prescribed for the treatment of caries, hypersensitive teeth as well as gingivitis.
Unfortunately, in spite of its promising results, the effective use of SnF.sub.2 has been drastically limited by its inherent instability in the presence of oxygen, water, abrasives etc.
In addition to the inherent instability of SnF.sub.2, most SnF.sub.2 products suffer from poor patient compliance, attributed in part to the nonaqueous carriers required to maintain activity, to the metallic taste of the product, as well as to the methods of application, which usually include a brushing step separate and apart from the use of a dentifrice. For example, brush-on SnF.sub.2 gels require the patient to brush at least four times/day, i.e., twice with the gel and twice with a regular dentifrice. Compliance in such a treatment regimen drops about 30%, an unacceptable level, as documented by Hastrieter's review of Wolf et al.'s 1989 Gel-Kem study.
With the advent of fluoride in water and fluoridated dentifrices, gum disease, gingivitis, hypersensitive teeth, root caries in the elderly and candida disorders in denture wearers, have replaced caries in children as the dominant oral care concerns of the '90's requiring special treatment. For example, a recent NIH survey established 90% of adults 65 or older have some form of gum disease, and over 123 million adults in the U.S. suffer from gum disease. Moreover, one out of six adults suffer from hypersensitivity at one time or another, while ten million adults are chronic sufferers. Additionally, the millions of adults who undergo periodontal treatment, or have their teeth cleaned, experience hypersensitivity discomfort ranging from an uncomfortable feeling to severe pain. Most denture wearers suffer from "denture breath" attributed in part to Candida sp. colonization of denture plaque and/or plaque-like coatings on dentures.
Recent reviews on dentine hypersensitivity have deduced that the transmission of pain stimuli across dentine is by a hydrodynamic mechanism. This is confirmed by the open tubules (microscopic openings) present at the dentine surface of sensitive teeth (and not present in normal teeth). Various stimuli cause fluid movement in these tubules which activate nerve endings in the pulp.
Considerable evidence has accumulated in the past 20 years to show that topical applications of SnF.sub.2 reduce S. mutans levels as well as demonstrate antiplaque properties. These antiplaque and antigingivitis benefits of SnF.sub.2 appear to be related to frequent, i.e., several times/day treatment with SnF.sub.2.
Root caries in the elderly is attributed to the recession of gums and is a common condition in the elderly that fortunately does respond to fluoride treatment. Candida sp. yeast disorders are estimated to occur in approximately 90% of denture wearers. These disorders lead to, or are associated with, stomatitis and thrush (candidiasis).
There is therefore a definite need in the art for oral hygiene preparations containing microbially active SnF.sub.2 that retain the desired antibacterial activity over the use life of the preparations. There is also a need in the art for oral hygiene preparations containing microbially active SnF.sub.2 that are pleasant to use, encourage compliance and support frequent usage throughout the day. There is a further need in the art for new methods of treating caries, coronal caries, gingivitis, plaque buildup, hypersensitivity and Candida sp. infections of denture plaque with microbially active SnF.sub.2 products in various forms.
There is a further need in the art for delivery vehicles for microbially active SnF.sub.2 which achieve rapid transport of SnF.sub.2 into fissures, crevices in dentures and other prosthesis where the microbial activity of SnF.sub.2 can be employed to fight plaque and disrupt the colonization of denture plaque by yeast type organisms while protecting the SnF.sub.2 from degradation of its microbial activity.
In view of the foregoing it is an object of this invention to provide an oral hygiene preparation containing a microbially active form of SnF.sub.2 for treating caries, gingivitis, plaque buildup hypersensitivity and Candida sp. infections of denture plaque.
It is also an object of this invention to provide an oral hygiene preparation containing microbially active SnF.sub.2 that is pleasant to use, encourages compliance and repetitive usage.
It is a further object of this invention to provide an effective method for treating caries, gingivitis, hypersensitivity, plaque buildup and Candida sp. infections of denture plaque.
It is still a further object of this invention to provide a compatible vehicle for microbially active SnF.sub.2 that permeates crevices etc. in dentures and denture plaque to deliver the active SnF.sub.2 so it can fight denture plaque and control colonization of denture plaque by Candida sp. organisms.
It is yet another object of this invention to provide a method of manufacturing oral hygiene preparations containing a microbially active form of SnF.sub.2.